Volt Rated at 93 MPGe, Leaf at 99 MPGe
By Chris Haak
This past week, the EPA released the long-awaited official mileage estimates for the two newest kids on the block, the Nissan Leaf and Chevrolet Volt. Because both cars are capable of running without burning gasoline (in fact, the Leaf cannot use gasoline at all), many were curious as to how the Monroney stickers would turn out for these two trendsetting automobiles. So now we have the answers, and they are probably more realistic and more relevant when comparing against other cars than some of the initial claims that had been thrown out by both GM and Nissan.
Far from the 230 miles per gallon claim that GM threw out there about the Volt over a year ago (to the chagrin of the EPA, which had, at the time, not been anywhere near finalizing their methodology to establish comparable fuel-economy scores), the Volt came in at a MPGe (miles per gallon equivalent) of 93 miles per gallon (combined city/highway) when running in EV mode, with an estimated range of 35 miles. In gas-only mode (known as “charge-sustaining mode” in Volt parlance, the EPA estimates a city/highway combined 37 miles per gallon, with a range of 344 miles. Altogether, starting with a full battery and a full tank of gas, the Volt should travel 379 miles before needing a fillup. The EPA also estimates a 60 mile per gallon composite between EV and gasoline propulsion.
For the Leaf, the EV number is even further from Nissan’s 367 MPG fantasy number that Nissan threw out in response to Chevy’s 230 mile per gallon claim. The Leaf came in at 99 MPGe combined, which breaks down to 106 MPGe city and 92 MPG3 highway ratings. The EPA also estimates a 73 mile range, which is below the company’s claims of 80-100 miles.
The new labels are similar to what consumers are used to seeing from more conventional vehicles, but offer some additional information. For instance, both cars’ labels provide charging time estimates at 240 volts (seven hours for the Leaf, four hours for the Volt). The EPA assumes a cost per kWh of 11 cents, and provides an annual cost estimate for the Volt under each mode, and for the Leaf. With that electricity cost assumption, the Volt would cost $601 to drive 15,000 miles per year in EV-only mode, and the Leaf would cost $561. Assuming $3.20 for each gallon of premium unleaded that the Volt requires for its gasoline engine, it would cost $1,302 to travel 15,000 miles per year in charge-sustaining mode only. In all likelihood, the reality would fall somewhere between the two numbers for the Volt, depending upon how it is driven.
Another nice feature on the labels, though admittedly buried in the fine print, is consumption data rather than only economy data. The Leaf consumes 34 kWh per 100 miles, and the Volt consumes 36 kWh per 100 miles in EV mode and 2.7 gallons per 100 miles. Most countries around the world present fuel consumption data (amount consumed per a distance, for example liters per 100 km) rather than fuel economy data (distance per a unit consumed, for example miles per gallon), so this is an important step in unifying expectations of consumers around the world.
Coming up with a way to present fuel economy for vehicles that don’t use fuel (or, in the Volt’s case, don’t always use fuel) wasn’t an easy challenge, and there are sure to be a number of critics of the EPA’s methodology. GM “worked with” the EPA in coming up with a relevant and useful label, but the fact that the Volt’s final number was less than half of GM’s 230 MPG claim may indicate that there was no undue influence on the General’s part in the process. To me, the stickers do a reasonably-good job of distilling complex information into a summary that makes comparisons with conventional vehicles.
